Learning AlmaLinux - History, Background & Why You Need It

#Introduction

In the previous episode, Episode 0, we set up our environment: making sure your basic Linux skills are ready, preparing a VM or VPS lab, and verifying that your AlmaLinux system runs well. In this episode we'll pause from hands-on work for a moment and answer the most fundamental question: why does AlmaLinux exist? Without understanding the problem it's meant to solve, you'll only be memorizing commands without ever understanding when and why they're needed.

We'll trace the history of AlmaLinux's birth, understand what a "RHEL rebuild" is, see how the AlmaLinux OS Foundation manages this distribution, and honestly assess why thousands of companies and administrators choose it for production systems. As the saying goes, we need to understand the past so we don't repeat the same mistakes in the future.

#The Origin: The Demise of CentOS Linux

AlmaLinux's story is inseparable from the fate of CentOS Linux. For years, CentOS was the top choice for admins who wanted a RHEL-compatible operating system without paying for a license. However, in December 2020, Red Hat announced a change of direction: CentOS Linux would no longer be a stable RHEL rebuild, and its focus shifted to CentOS Stream — a rolling distribution positioned between Fedora and RHEL.

This decision caused major upheaval in the community. Thousands of production servers depending on CentOS had to find a replacement, and time was short. Out of that vacuum, two major projects emerged almost simultaneously: AlmaLinux and Rocky Linux.

#What Is a RHEL Rebuild?

To understand AlmaLinux, you need to understand the term rebuild. Red Hat Enterprise Linux (RHEL) is a commercial distribution — its source code is publicly available, but the official builds are paid. A rebuild project takes that source code, rebuilds it without Red Hat's logos and branding, and distributes it for free.

This means every package in AlmaLinux is built from the same SRPM (Source RPM) as RHEL. The result is a system that is 1:1 binary-compatible: binaries compiled for RHEL run flawlessly on AlmaLinux, and vice versa. Applications tested on RHEL are guaranteed to run on AlmaLinux without any changes.

cat /etc/os-release

The output will show ID=almalinux and a VERSION_ID matching the release you're using. This is the first proof that you're running AlmaLinux, not RHEL — even though the two are indistinguishable at the binary level.

#AlmaLinux OS Foundation: Community, Not a Vendor

One of the things that sets AlmaLinux apart from its predecessor is its governance model. AlmaLinux is managed by the AlmaLinux OS Foundation — a non-profit organization owned and run by the community, not by a single vendor or company.

This principle matters because it brings three tangible benefits:

1. Transparency — the entire build process and governance decisions are open and publicly auditable.
2. Independence — no single company can change the direction of the distribution for its own commercial interests.
3. Continuity — decisions are made by a community with a long-term stake in the distribution's stability.

#Why AlmaLinux: What Makes It Worth Using

Now that we understand its history, let's examine the practical reasons AlmaLinux is worth choosing for production.

#1:1 Bug-for-Bug Compatibility with RHEL

AlmaLinux is built from the same RHEL source, so its compatibility isn't just "mostly the same" — it's bug-for-bug compatible. System behavior, including known quirks and bugs, is consistent with RHEL. This is crucial if you're running enterprise applications: whatever runs on RHEL will run identically on AlmaLinux.

#Free with No License Costs

RHEL is a paid product that requires a subscription. AlmaLinux is free to use on any number of servers — no license fees, no minimum node count, no limitations. This makes it ideal for labs, homelabs, and large-scale production with limited budgets.

#10-Year Lifecycle

Every major AlmaLinux release is supported for 10 years — a combination of Full Support and Maintenance Support. You won't be forced to upgrade every few months. This is very important for enterprise environments that prioritize stability.

#ELevate: Migration Without Reinstallation

AlmaLinux developed ELevate — a Leapp-based tool that enables in-place migration between major versions, for example from 8 to 9 or 9 to 10, without needing to reinstall. This differs from most major upgrades, which usually require a reinstall. We'll cover the full details of ELevate in episode 20.

#A Brief Comparison with Alternatives

To give you perspective, here's where AlmaLinux stands among several alternatives:

We'll cover an in-depth comparison between AlmaLinux and its competitors thoroughly in episode 22, the closing episode of this series.

#Common Pitfalls

1. Thinking AlmaLinux is "pirated RHEL". Completely wrong — AlmaLinux is a legal distribution built from source code that is genuinely public. Its license and model are transparent.
2. Thinking AlmaLinux is the same as CentOS Stream. CentOS Stream is a rolling upstream; AlmaLinux is a stable rebuild that occupies exactly the place of the old CentOS Linux.
3. Thinking "1:1 compatible" means all packages are identical. The branding differs, and some Red Hat-specific packages aren't available — but binary compatibility is the main guarantee.
4. Forgetting to check the version before making decisions. Always run cat /etc/os-release to confirm the version running on your servers.
5. Ignoring the minor release schedule. AlmaLinux releases minor versions periodically (for example 10.1, 10.2). Delaying minor updates for too long means missing security backports and important bug fixes. Set up a regular update schedule from the start, and use dnf5 check-update to monitor available updates.

Remember: almost every problem that arises on AlmaLinux has an answer in the official documentation at docs.almalinux.org or the community forums. Being a good administrator isn't about memorizing every command — it's about knowing where to find the right answer.

By avoiding the common pitfalls above, your journey into AlmaLinux will be much smoother from this very first episode.

#Conclusion

In this episode 1 we've traced why AlmaLinux was born: the demise of CentOS Linux in December 2020, the birth of AlmaLinux as a free community-managed RHEL rebuild, the release journey from 8.0 to 10.2, and the practical reasons it's worth using in production — 1:1 compatibility, free, transparent, 10-year lifecycle, and ELevate.

Key takeaways:

• AlmaLinux was born as the answer to the retirement of CentOS Linux in late 2020.
• It is a RHEL rebuild built from the same SRPMs — 1:1 binary-compatible.
• Managed by the AlmaLinux OS Foundation, which is non-profit and community-owned — not by a single vendor.
• Its main advantages: free, transparent, 10-year lifecycle, and ELevate for reinstall-free migration.
• Verify identity with cat /etc/os-release on every machine.

This understanding of the "why" becomes the foundation for understanding "how" AlmaLinux works. In the next episode, Episode 2, we'll cover core concepts & main architecture — breaking down the build process from RHEL SRPMs into AlmaLinux repositories, understanding the roles of the kernel, dnf5, systemd, SELinux, firewalld, Cockpit, down to the BaseOS and AppStream repositories that make up the whole system. Stay motivated, because this is where you'll start truly understanding how AlmaLinux works from the inside!